Laminated packer



p 1969 c. M. FURGASON ETAL 3,464,709

LAMINATED FACKER 2 Sheets-Sheet 1 Filed May 20, 1966 5 3m W 9% fl/ 0 5Mu MN 0 m ATTORNE Y Se t. 2, 1969 c. M. FU-RGASON ETAL 3,464,709

LAMINATED PACKER Filed May 20, 1966 2 Sheets-Sheet 2 (0/*/ M furyaJanCar/ J fcA e/w'ao I V VI'LV TORS ATTORNE Y United States Patent3,464,709 LAMINATED PACKER Carl M. Furgason and Carl J. Eckenrod,Houston, Tex., assignors, by mesne assignments, to US. Industries, Inc.,a corporation of Delaware Filed May 20, 1966, Ser. No. 551,738 Int. Cl.F16j 15/32, 15/56 US. Cl. 277-213 6 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to packers, particularly toroidal packersdesigned for resisting high temperatures and/0r pressures, and to themethod of constructing the same.

Devices for packing off or sealing clearances between working parts, forinstance, regions of oil wells, usually embody elastomeric body memberswhich are radially deformable by axial pressures applied thereto so asto elfect the desired seal. The basic material often used is rubber,either natural or synthetic. However, such material is decomposed orotherwise deteriorated under high temperature conditions to which thepacker may be exposed, for instance, in steam stimulation of oil and gaswells.

Accordingly, an object of the present invention is to provide a packerbody, particularly a toroidal packer, which will withstand temperaturesas high as 400 or 500 degrees or more without substantial deterioration.

Another object is to provide a packerconstructed principally of adurable material such as asbestos fabric which is not stretchable orpressure deformable to any substantial extent under the operatingconditions to which it is subjected, yet which can be inserted into awell and radially expanded to perform its pack-off function.

A related copending application Ser. No. 551,793 filed May 20, 1966, inthe name of Carl M. Furgason discloses the concept of combining with apacker, consisting at least in part of synthetic rubber, a particulatemetal, for instance, powdered iron, which will be aflected by themoisture and/or other ingredients of the well fluid to form a newchemical compound. This residual substance, for instance, rust, is ofgreater volume than the combined metal and thus tends to compensate forshrinkage in the packer body due to decomposition of the rubber underhigh temperature conditions.

The present application is directed to the high temperature resistantpacker body itself and the method of constructing the same. This body isconstructed substantially of stacked, frus'to-conical laminae offlexible asbestos sheeting with intervening binder material. The outerportions of the frusto-conical laminae are circumferentially corrugatedor crimped, as by reducing the diameter thereof, to accommodate radialexpansion of the packer body without stretching of the asbestos fabricmaterial. Suitable means, for instance, that disclosed in the copendingapplication Ser. No. 551,794 filed May 20, 1966, may be utilized toprovide the necessary radial expansion of the packer body.

In the accompanying drawings which illustrate the invention,

3,464,709 Patented Sept. 2, 1969 section through a more-or-lessconventional packer embodying the invention;

FIG. 2 illustrates an asbestos fabric blank utilized in constructing thepacker;

FIG. 3 is a perspective view showing the blank of FIG. 2 formed into afrusto-conical lamina;

FIG. 4 is a half elevation and half vertical transverse section on anenlarged scale showing a step in formation of the packer;

FIG. 5 is an enlarged vertical transverse half section illustrating thecompleted packer body;

FIGS. 6 and 7 are detail sectional views illustrating steps in theconstruction of the packer; and

FIG. 8 is a half longitudinal section illustrating a modification;

FIG. 9. is a perspective view of a lamination in the shape assumed wheninserted in a contracting cylindrical mo d.

FIG. 1 illustrates a bore hole 7 in the earth into which is extended acasing 8 cemented as at 9 in the usual manner. A tubing string 10extends into the casing and is joined to the mandrel portion 11 of apacker with which the present invention is concerned. Received about thepacker are spaced collars 12 and 13 to which are pivotally secured slipelements 14 and 15 having toothed or wickered elements 16 and 17 attheir free ends.

In a downwardly-seating packer, ripper collar 12 will be secured to themandrel 11 which will be arranged to telescope through lower collar 13,which, in turn, will be restrained to a more-or-less fixed position withrespect to the casing by suitable friction or other means (not shown).In an upwardly-seating packer, lower collar 13 will be fixed withrelation to mandrel 11 which will slide through upper collar 12. Alsoslidably received upon the mandrel are expander wedges 19 and 20 betweenwhich there are provided the sealing packer bodies 21. The arrangementis such that, upon telescoping of mandrel 11 through either collar 12 or13, as explained, slip elements 16 and 17 will be caused to lodgeagainst the inner wall of the casing and axial pressures will be appliedto the packer bodies 21 to cause radial expansion thereof into sealingengagement with the casing.

Packer bodies 21 are constructed principally of stacked, frusto-conicallaminae 24, of the type shown in FIG. 3, which are formed by stapling orotherwise securing together the end portions 25 and 26 of acrescent-like blank 27 cut from a sheet of asbestos fabric or otherdurable sheeting. These laminae are then compacted in a mold 29, asshown in exaggerated scale in FIG. 4, having a re-entrant bottom 30.Each lamina 24a, 24b, etc., is provided with coatings including layers31 of particulate metal, preferably powdered iron, and thin rubberlayers 32 which serve as binders. The rubber, preferably synthetic, isheavily loaded, preferably up to percent, with inert filler such ascarbon black. The assembled layers are then subjected to heat andpressure for molding the whole into a coherent mass with the abuttingrubber layers merged and extending into the interstices of the powderedmetal and fabric layers.

While the asbestos fabric of which the laminae 24 are constructed cannotbe stretched substantially without injury, the molded packer body isprovided with radial expansibility by the utilization of a mold 29 whichis of slightly less diameter than the peripheral diameter of the laminae24. Thus, the outer portions of these laminae will be bent more acutelytoward the axis of the packer body as the peripheries are reduced andlaterally corrugated or crimped, as indicated at 33 in FIGS. 1 and '9.The binder material is of sufficient plasticity, at least under workingconditions of temperature and pressure, to permit flexing of thelaminations and radial expansionof thebody when subjected to radialpressures, as will be explained.

FIG. shows a completed packer unit 21 including the separately-formedupper and lower body parts 34 and 35 which are identical but reversed sothat only the upper part 34 need be described in detail. First, twolaminated body sections 36 and 37, shown respectively in FIGS. 6 and '7,are molded in the manner illustrated in FIG. 4. The upper tip portion 38of section 36 is then cut off as are the lower tip portions 39 and 40 ofsection 37. Tip portion 40 is discarded. Truncated sections 36 and 37are then assembled in a toroidal mold in the relationship shown in FIG.5 to form the body part 34. The base periphery 43 of upper section 36 isradially contracted, as shown, so as to fit within and axially overlapthe peripheral portion 44 of lower section 37. Between the two sectionsthere is provided a thin, frusto-conical sheet 45 of binder rubber. Inthe inner toroidal space between sections 36 and 37 and the mandrelthere is inserted a filler ring 46 of trapezium section, and the cutofftip portion 39 previously mentioned, is inserted and bonded in positionas shown. Each of the body parts 34 and 35 require two laminatedsections 36 and 37. The four cut-off tips 38 and 39 from these sectionsare used as internal fillers, as shown.

The laminated body is practically non-deformable radially under axialforces incident to normal operations. Accordingly, the inner filler ring46 is of material which is pressure deformable in order to respond toaxial operating forces applied thereto, as in setting the packer, tocause axial contraction and radial expansion of the body part 34 and,particularly, the intermediate, axially-overlapping corrugated portions43 and 44 thereof. The upper edge 47 of the expander insert is biased asshown to reduce to a certain extent the quantity of rubber in theassembly and the resultant space of triangular section is filled, asnoted, by the otherwise wasted tip portion 38 of the laminated bodysection.

In order to provide a packer body of greater over-all length, two of thebody parts 34 and 35 are assembled in reversed, end-to-end relation withsuitable binder and spacer laminations 48 therebetween.

While the packer as herein disclosed, at normal atmospherictemperatures, will be quite hard due to the large amount of inert fillermaterial used in the binder, at elevated temperatures such as 300 to 500degrees F., encountered, for instance, in steam stimulation of a well,this body will be sufficiently pressure deformable, i.e., plastic, torespond to axial setting pressures for providing the desired radialsealing action. The Words plastic and plastically deformable areadjectives used herein as to define the necessary pressure deformabilityof the insert body rings 46. While heavily-filled, synthetic rubberworks well, other elastomers, or even putty-like material, might be usedif adequately restrained. Laminations 32, preferably, are permeable toconduct ambient fluid into contact with particle layers 31, as explainedin said application Ser. No. 551,793.

FIG. 8 shows a modification in which the inserted filler ring consistsof a toroidal bag 50 filled with small globular particles, .as balls51.,Suitable wedging expanders might also be utilized to effect theradial sealing action of the body parts.

The invention may be modified in various respects as will occur to thoseskilled in the art, and the exclusive use of all modifications as comewithin the scope of the appended claims is contemplated.

We claim:

1. A toroidal packer body for reception about and upon a mandrelcomprising a pair of body parts each consisting of stacked,frusto-conical laminations of flexible, non-stretchable, durable sheetmaterial disposed acutely with respect to the mandrel and withintervening binder, the body parts being oppositely disposed with. theirperipheral bases laterally corrugated and telescopingly interfittingleaving an inner toroidal space between the adjacent ends of the parts,and afiller ring inserted in said space.

2. A packer body as described in claim 1 in which said body partlaminations are embedded in elastomeric material whereby said parts areyieldably form-sustaining.

3. A packer body as described in claim 1 in which said laminations areof high temperature resistant material.

4. A packer as described in claim 3 in which said laminations are ofasbestos sheeting.

-5. A packer body as described in claim 1 in which said filler ring isof plastic material and is radially de formable under axial forcesapplied thereto for expanding said body parts into sealing engagementwith an ambient wall.

6. A packer comprising axially-stacked laminations of flexible,substantially non-stretchable sheet material with intervening binderforming a coherent, toroidal, nonplastically-deformable body, saidlaminations being acutely angled with respect to the axis of the packerand the peripheries of said laminations being laterally corrugated topermit radial expansion thereof, and a plastically-deformable ringlodged in said chamber and adapted to expand radially when axiallypressured to press said lamination peripheries outwardly.

References Cited UNITED STATES PATENTS 1,662,336 3/1928 Reynolds277-1164 X 2,388,520 11/1945 Bowie. 2,537,230 1/1951 Mueller 277233 X213,739 4/1879 Colby 277-233 X 3,068,942 12/1962 Brown 277ll6.2 X

( FOREIGN PATENTS 1,873 1912 Great Britain.

LAVERNE D. GEIGER, Primary Examiner JEFFREY S. MEDNICK, AssistantExaminer US. Cl. X.R. 277123, 124, 233

